Cylinder construction for aircooled engines



Dec. 1, 1936. Q BROWN 2,062,392

CYLINDER CONSTRUCTION FOR AIR-COOLED ENGINES Filed Sept. 12, 1955 3 Sheets-Sheet l ATTORNEYS Dec. 1, 1936. c. 5. BROWN CYLINDER CONSTRUCTION FOR AIR-COOLED ENGINES Filed Sept. 12, 1935 3 Sheets-Sheet 2 ENTOR. M

ATTORNEYS.

Dec. 1, 1936. c. 5. BROWN CYLINDER CONSTRUCTION FOR AIR-COOLED ENGINES Filed Sept. 12, 1935 3 Sheets-Sheet 3 INgTOR. /7m

ATTORN Y5 Patented Dec. 1, 1936 UNITED STATES- CYLINDER CONSTRUCTION FOR AIR- COOLED ENGINES Charles S. Brown, Syracuse, N. Y.

Application September 12, 1935, Serial No. 40,301

4 Claims.

This invention relates to air cooled internal combustion engines, and has for its object a cylinder construction in which one wall, as the head, is a block of metal of high heat conductivity of sufiioient cubic capacity to quickly absorb or.

conduct the heat away from the combustion chamber and store excess heat generated in the use of the engine under normal and. abnormal conditions, so that under abnormal conditions the excess heat is carried away from the bore of the cylinder or from the combustion chamber and stored temporarily or momentarily until it is removed bya gentle air current as distinguished from a blast of air generated by a heavy duty fan. For illustration, for the necessary mechanical strength, a head of one-half inch thickness may be required. However, the heat generated would be confined within the head, and under varying load conditions, the head would become abnormally hot. By making the head of a thickness greater than required to give the necessary mechanical strength, a heat storage block is provided for conducting the heat to a great and adequate heat exchanging surface, as flanges. An air blast of maximumvolume and velocity is required to cool the thinhead, and only' a slowly moving gentle current is necessary to cool the head with a body for storing the excess heat." 1

It further has for' its object a cylinder construction in which the head consists of a block large enough exclusive of the heat radiating flanges to absorb excess heat.

By excess heat is meant the heat that under abnormal conditions is not radiated away from the cylinder sufliciently for the cylinder to cool substantially thesame extent as it cools under normal running conditions. i f i By abnormal conditionis meant the condition such as is encountered when the motor .vehicle is running up a long steep grade or under a heavy load, so' that heat is generated and accumulates much faster than when running on a normal road the accompanying drawings in which like char acters designate corresponding parts in all the views.

Figure 1 is a transverse sectional view of an engine cylinder embodying this invention.

Figure 2 is a sectional view on line 2-- -Z, Fi g ure 1.

Figure 3 is a side elevation looking to the left, Figure 1. v

Figure 4 is an inverted plan view oi! the head block. j

Figure 5 is a plan view of a pair of blocks arranged in line or the cylinder arrangement of a four cylinder engine or a bank of cylinders of a V'-type eight cylinder engine.

block and a head block, the head block being pref- I erably detachably secured to the cylinder block.

Both the cylinder and head blocks are formed of I a metal having high heat conductivity, as aluminum or aluminum alloy, and the barrel block may,

barrel block is formed with an offset 3 on one side I thereof, in which the intake and exhaust ports 4, 5 are formed. This offset 3 is of greater bulk or thickness than would ordinarily be provided in L head engines, and is of suflicient cubic capacity to quickly absorb the heat from the valve passages,

' especiallyfrom the' exhaust valve passages, and

to distribute the heat throughout the body of the oiiset'3, it being understood that the exhaust port for the hot exhaust gases is considerably hotter than the cool intake passage, and therefore, ordinarily, there is a differential expansion and contraction of the metal around the ports; By providing a body of metal 3 of suflicient-heat absorptivity 'or heat absorbing and storing capacity, the heat is radiated or distributed throughout the ofiset 3. Thus differential expansion and contraction of 'difierent parts of the ofiset 3 is avoided. Some of. the flanges 2 extend on the outer surface of the ofiset 3, as seen in Figures 2 and 3. This feature in regard to the body of metal 3 constitutes part of the subject matter of a companion application Serial No. 40,127, filed September 11, 1935, which application also includes assubject matter a different specific form of heat absorbing head from that forming the subject matter of this application. 1

l designates the head block. This is a body of metal having high heat conductivity, as aluminum or aluminum alloy. It is formed with the combustion chamber 8 and the amount of metal used is considerably greater than required to confine the combustion chamber 8 and give the required strength to the head, and is sufficient in bulk or heat absorbing and storing capacity to provide for storage of the excess heat or maximum heat developed in the engine under extreme or abnormal load conditions. The heat absorbing capacity of the head block 'I is such that the excess heat is conducted away from the wall of the combustion chamber and stored under heavy load conditions, so that the combustion chamber does not become overheated. When the load conditions are alleviated, the stored heat is rapidly radiated to the air. The principle may be explained by the following experiment. Apply the flame of a blow torch to one side of a sheet of metal. The metal will become red hot in a short time. Apply the flame of the blow torch to one side of the metal block of considerable thicknesssay one inch, of same area on the side to which the flame is applied, as the metal sheet. It will be found impossible to heat the block to the extent that it will have even a dull color.

As here shown, the head is oblong or rectangular in general form in cross section in order. to provide a large exterior surface area for heat radiating flanges 9. The head is thus substantially of uniform thickness throughout its area and of such size as to absorb the excess heat generated by the engine when working under abnormal conditions of load. Said flanges are vertical in a direction widthwise of the flanges and are preferably arranged to extend horizontally over the head. The'flanges also extend over the edge of at least one end of the block, as at I0. some of the flanges are cut away to provide spaces'for giving access to the cap screws II by which the head block is secured to the barrel block. The flanges are also cut away for the spark plugs, not shown, which may be mounted in the head in any well known manner. The flanges 9 are approximately of the same metal as the solid body of the head block I and may be integral therewith, but in order to provide a maximum number of these flanges, and hence the greatest possible heat radiating surface, these flanges are preferably of sheet aluminum alloy with their margins embedded in the head block 1 during casting of the head block. The

heat radiating flanges provide air passages in the head block.

, In the engine construction here shown the cylinders are arranged in pairs, that is, each barrel block is formed with a pair of cylinder bores. The cylinder blocks are preferably spaced apart, as at l2, in order to permit air to pass between the barrel blocks, and in order that the barrel blocks may be as close together as possible and yet provide the air passage, the flanges I II are omitted at the confronting ends of the barrel blocks.

Heretofore, it has been thought necessary, for the operation of high power air cooled engines. to cool the engine by a blast of air of maximum volume and velocity. A fan for creating the air blast, not only requires considerable power but also; even though carefully designed, does not move the greatest amount of air when the engine is generating the greatest amount of heat, and although the amount of air moved bythe 'fan does not depend entirely upon the speed,

nevertheless it depends, to a large extent, upon the speed, and when the engine is turning slowly under a heavy load, the air is oftentimes insuflicient to cool the engine.

By this head block construction by which heat storage is provided, the heat under ordinary conditions is conducted quickly from the cylinder walls or the walls of the combustion chamber, and the heat under abnormal conditions is conducted from the walls of the combustion chamher and temporarily stored in the body of metal constituting the head. The excess heat is being constantly radiated therefrom and efflciently removed by a gentle air current, as distinguished from a powerful air blast. A circulating fan analogous to that of the radiator fan of a water cooled engine creates a sufficient air circulation to cool the head, even underabnormal conditions. Owing to the thickness of the head. the internal heat is efliciently conducted from the combustion chamber under all conditions and the heat does not rise in the interior oi the cylinder to a point where the engine overheats.

What I claim is:

1. A cylinder head construction for internal combustion engines comprising a block of metal having relatively high heat conductivity and being of such size as to absorb the excess heat generated by the engine when working under abnormal conditions of load.

2. An air cooled cylinder head construction for internal combustion engines and the like, said head comprising a block of metal having high heat conductivity and being of substantiallyuniicrm thickness throughout its area and being of such size as to absorb the excess heat generated by the engine when working under abnormal conditions of load.

3. A cylinder head construction for internal combustion engines and the like comprising a block. of metal having high heat conductivity and being of such size as to absorb the excess heat generated by the engine when working under abnormal conditions of load, the head having heat radiating flanges substantially throughout its width.

4. An air cooled cylinder head construction for internal combustion engines and, the like, said head comprising a block of metal having high heat -conductivity and being of substantially uniform thickness throughout its area and being of such size as to absorb the excess heat generated by the engine when working under abnormal conditions of load, the head having heat radiating flanges substantially throughout its width.

7 CHARLES S. BROWN. 

